局部麻醉剂——对氨基苯甲酸的合成研究

Study of synthesis of local anesthetics para aminobenzoic acid

本文以对硝基苯甲酸和Na2S为原料,用还原技术合成对氨基苯甲酸。经过加热,冷却,抽滤,重结晶等步骤得产品,通过测熔点的方法对产品进行表征。考察了还原剂用量,溶剂用量,反应时间,反应温度,结晶溶液pH值对其收率的影响。研究结果表明:当对硝基苯甲酸与Na2S的摩尔配比为1∶2.0、对硝基苯甲酸与NaHCO3的摩尔配比为1∶3.0、反应时间60℃、反应温度60min、结晶溶液pH值为5时,对氨基苯甲酸的收率较高。

Amino acid was synthesized by reduction technology with the nitro benzoic acid and sodium sulfide as raw material. After heating,cooling,filtering,heavy crystallization steps,the products were characterized by melting point measurement method. The dosage of reductant,dissolve of dosage,reaction time,reaction temperature, crystallization solution pH value were investigated on its yield .The results show that： When the p-nitrobenzoic acid and molar ratio of sodium sulfide was 1：2.0,the p-nitrobenzoic acid and molar ratio of sodium bicarbonate was 1：3.0, reaction temperature 60℃, reaction time 60min, the crystallization solution pH=5, yield of the amino acid was higher.